I've been working hard, with the help of telerik support, trying to extend the features of RadDocument. Please find my latest code sample download link here
It took me quite some time to learn and make these features so this should help speed things up for you.
I have mainly be building up a library of custom annotation features, but there are also other additions.
Here are my methods:
Feel free to let me know if you find any errors or more efficient ways to achieve the above.
Please upload your code if you extend the features of this code sample. Every little helps.